1. Field of the Invention
This invention relates to a stringing for a sports racket such as, but not limited to, a tennis racket or a racket-ball racket.
2. Background Information
A patent search was conducted, and the following patents were discovered:
______________________________________ 3,834,699 09/10/74 Pass 3,921,979 11/25/75 Dischinger 4,005,863 02/01/77 Henry 4,078,796 03/14/78 Gibello 4,168,065 09/18/79 Goransson 4,249,731 02/10/81 Amster 4,368,886 01/18/83 Graf 4,377,288 03/22/83 Sulprizio 4,391,391 07/05/83 Robaldo 4,458,898 07/10/84 Boden 4,593,905 06/10/86 Abel 4,597,576 07/01/86 Haythornthwaite 4,681,319 07/21/87 Zilinskas 4,685,676 08/11/87 Boden 4,741,531 05/03/88 Szedressy 4,863,168 09/05/89 Anderka et al. 4,913,430 04/03/90 Lichtenstein 4,949,968 08/21/90 Korte-Jungermann 5,141,227 08/25/92 Flamm 5,141,228 08/25/92 Soong 5,158,285 10/27/92 Flamm 5,303,918 04/19/94 Liu 5,470,066 11/28/95 Soong ______________________________________
Conventional tennis rackets are strung with strings passed above and below each other to produce a woven string network. Since the strings are not bonded at their crossover points, the pattern of the string network may deform when the ball is struck by a racket with an upwards or downwards component of motion, such as that used by players wishing to place spin on the ball. The movement of the strings relative to one another produces wear through attrition and leads to premature string failure. This effect is accentuated when the tennis game is played on clay, where clay micro particles are brought to the racket by the tennis ball and, upon reaching the location of string attrition, accelerate the process of wear.
U.S. Pat. No. 4,741,531 by Szedressy and 4,949,968 by Korte-Jungermann permit replacing a single broken string without rebuilding the entire string network. These designs share the basic idea of building the string network with individual string segments that traverse the string network only once and are attached to the racket frame at oppositely disposed locations via a fixing means. In both cases, extra tension must be applied in the process of stringing the racket in order to compensate for a string shortening caused by a yield of the fixing means in the string axial direction following the release of the string by the string tensioning means. The axial yield alters the string tension and complicates the stringing process.
As will be seen from the subsequent description of the preferred embodiedment of the present invention, these and other shortcomings of the prior art are overcome.